COOL2015 - List of Keywords (electron)

Paper	Title	Other Keywords	Page
MOXAUD02	Experimental Observation of Longitudinal Electron Cooling of DC and Bunched Proton Beam at 2425 MeV/c at COSY	proton, simulation, experiment, vacuum	10
	V.B. Reva, M.I. Bryzgunov, V.V. Parkhomchuk BINP SB RAS, Novosibirsk, Russia V. Kamerdzhiev, T. Katayama, R. Stassen, H. Stockhorst FZJ, Jülich, Germany
	The 2 MeV electron cooling system for COSY-Julich started operation in 2013 years. The cooling process was observed in the wide energy range of the electron beam from 100 keV to 908 keV. Vertical, horizontal and longitudinal cooling was tested at bunched and continuous beams. The cooler was operated with electron current up to 0.9 A. This report deals with the description of the experimental observation of longitudinal electron cooling of DC and bunched proton beam at 2425 MeV/c at COSY.
	Slides MOXAUD02 [10.860 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF02	The Green Energy Turbine as Turbo Generator for Powering the HV-Solenoids at a Relativistic Electron Cooler	solenoid, high-voltage, experiment, emittance	29
	A. Hofmann, K. Aulenbacher, M.W. Bruker, J. Dietrich, T. Weilbach HIM, Mainz, Germany V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia
	One challenge in the development of a relativistic electron cooler is the powering of components, e.g. HV-solenoids, which sit on different potentials within a high voltage vessel and need a floating power supply. Within a design study, BINP SB RAS Novosibirsk has proposed two possibilities to build a power supply in a modular way. The first proposal is to use two cascade transformers per module. One cascade transformer powers 22 small HV-solenoids; the second one should generate the acceleration/deceleration voltage. The cascade transformers are fed by a turbo generator, which is powered by a gas under high pressure which is generated outside of the vessel. The second possibility is to use two big HV-solenoids per module. In this proposal, the HV-solenoids are powered directly by a turbo generator. For both concepts, a suitable turbo generator is essential. A potential candidate for the turbo generator could be the Green Energy Turbine (GET) from the company DEPRAG, which works with dry air and delivers a power of 5 kW. At the Helmholtz-Institut Mainz two GETS are tested. After an introduction, we present our experience with the GET and give an overview of the further road map.
	Poster MOPF02 [3.424 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF03	Electron Lenses and Cooling for the Fermilab Integrable Optics Test Accelerator	optics, proton, space-charge, lattice	32
	G. Stancari, A.V. Burov, V.A. Lebedev, S. Nagaitsev, E. Prebys, A. Valishev Fermilab, Batavia, Illinois, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the US Department of Energy. Recently, the study of integrable Hamiltonian systems has led to nonlinear accelerator lattices with one or two transverse invariants and wide stable tune spreads. These lattices may drastically improve the performance of high-intensity machines, providing Landau damping to protect the beam from instabilities, while preserving dynamic aperture. The Integrable Optics Test Accelerator (IOTA) is being built at Fermilab to study these concepts with 150-MeV pencil electron beams (single-particle dynamics) and 2.5-MeV protons (dynamics with self fields). One way to obtain a nonlinear integrable lattice is by using the fields generated by a magnetically confined electron beam (electron lens) overlapping with the circulating beam. The required parameters are similar to the ones of existing devices. In addition, the electron lens will be used in cooling mode to control the brightness of the proton beam and to measure transverse profiles through recombination. More generally, it is of great interest to investigate whether nonlinear integrable optics allows electron coolers to exceed limitations set by both coherent or incoherent instabilities excited by space charge.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF05	A Cooling Storage Ring for an Electron-Ion Collider	ion, simulation, collider, booster	36
	J. Gerity, P.M. McIntyre Texas A&M University, College Station, USA
	Electron cooling offers performance advantages to the design of an electron-ion collider. A first design of a 6 GeV/u storage ring for the cooling of ions in MEIC is presented, along with some remarks on the particulars of electron cooling in this ring.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF06	Quantification of the Electron Plasma in TItan's Cooler Penning Trap	ion, detector, plasma, TRIUMF	39
	B.A. Kootte, B. Barquest, U. Chowdhury, J. Even, M. Good, A.A. Kwiatkowski, D. Lascar, K.G. Leach, A. Lennarz, D.A. Short TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada M. Alanssari Universität Muenster, Physikalisches Institut, Muenster, Germany C. Andreoiu SFU, Burnaby, BC, Canada J. Bale, J. Dilling, A. Finlay, A.A. Gallant, E. Leistenschneider UBC & TRIUMF, Vancouver, British Columbia, Canada D. Frekers Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, Münster, Germany G. Gwinner University of Manitoba, Manitoba, Canada R. Klawitter Heidelberg University, Physics Institute, Heidelberg, Germany T.T. Li UW/Physics, Waterloo, Ontario, Canada A.J. Mayer University of Calgary, NW Calgary, Alberta, Canada R. Schupp MPI, Muenchen, Germany
	Funding: Funded by Natural Sciences and Engineering Research Council of Canada (NSERC) Modern rare isotope facilities provide beams of shortlived radionuclides primarily for studies in the field of nuclear structure, nuclear astrophysics, and low energy particle physics. At these facilities, many activities such as re-acceleration, improvement of resolving power, and precision experimental measurements require charge breeding of ions. However, the charge breeding process can increase the energy spread of an ion bunch, adversely affecting the experiment. A Cooler Penning Trap (CPET) is being developed to address such an energy spread by means of sympathetic electron cooling of the Highly Charged Ion bunches to . 1 eV/q. Recent work has focused on developing a strategy to effectively detect the trapped electron plasma without obstructing the passage of ions through the beamline. The first offline tests demonstrate the ability to trap and detect more than 10⁸ electrons. This was achieved by using a novel wire mesh detector as a diagnostic tool for the electrons. * E.M. Burbidge et al, Rev Mod Phys, 29 547 (1957) V.V. Simon et al, Phys Rev C, 85 064308 (2012) * Z. Ke et al, Hyp Int, 173 103 (2006) **** U. Chowdhury et al, AIP Conf Proc, 1640 120 (2015)
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF08	Secondary Electron Measurements at the HIM Electron Cooler Test Set-Up	simulation, operation, dipole, optics	48
	M.W. Bruker, K. Aulenbacher, J. Dietrich, A. Hofmann, T. Weilbach HIM, Mainz, Germany
	The planned advances in electron cooling technology aimed at improving the operation of future hadron storage rings include an increase in electron beam current and acceleration voltage. A test set-up has been built at Helmholtz-Insitut Mainz (HIM) to optimize the recuperation efficiency of such high-current beams in energy recovery operation, requiring a thorough understanding of their interaction with external electric and magnetic fields, such as those found in a Wien velocity filter. Beam diagnostics are carried out using a BPM and current-sensing scraper electrodes. At present, the set-up can be successfully operated at U=17 kV, I=600 mA, showing a relative secondary electron current of about 2·10^-4. We present the current state of the project and its objectives for the foreseeable future.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF10	Design Beam Diagnostic System for Optical Stochastic Cooling at IOTA Ring	undulator, radiation, synchrotron, kicker	55
	K. Yonehara, V.A. Lebedev Fermilab, Batavia, Illinois, USA J.A. Maloney TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Validation test of optical stochastic cooling (OSC) with 100 MeV electron beam is designed at IOTA ring at Fermilab. A beam diagnostic system for the test is discussed in this paper. The beam position and bunch length will be measured by using a standard button-pickup BPM; while the beam emittance will be measured by using a CCD-based synchrotron light detector. Especially, accurate time measurement is essential to carry out OSC experiments with a single particle. Desired time resolution is the order of 100 ps to study the cooling decrement in various lattice parameters. SiPM is an attractive solid-state device to detect a time domain synchrotron radiation photon. It can realize a fast rise time < 100 ps with a short time width 1-2 ns FWHM and its quantum efficiency is > 40 % at 420 nm. The beam instrumentation required to tune timing in the OSC insert is also discussed. It is based on the interference of radiation coming from the pickup and kicker undulators.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF12	N-body Code to Demonstrate Electron Cooling	proton, ion, booster, emittance	59
	S. Abeyratne, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA B. Erdelyi ANL, Argonne, USA
	In the Electron Ion Collider (EIC), the collision between the electron beam and the proton, or heavy ion, beam results in emittance growth of the proton beam. Electron cooling, where an electron beam and the proton beam co-propagate, is the desired cooling method to cool or mitigate the emittance growth of the proton beam. The pre-booster, the larger booster, and the collider ring in EIC are the major components that require electron cooling. To study the cooling effect, we previously proposed Particles' High order Adaptive Dynamics (PHAD) code that uses the Fast Multiple Method (FMM) to calculate the Coulomb interactions among charged particles. We further used the Strang splitting technique to improve the code's efficiency and used Picard iteration-based novel integrators to maintain very high accuracy. In this paper we explain how this code is used to treat relativistic particle collisions. We are able calculate the transverse emittances of protons and electrons in the cooling section while still maintaining high accuracy. This presentation will be an update on progress with the parallelization of the code and the current status of production runs.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF13	Taper and Tuner Scheme of a Multi-Frequency Cavity for the Fast Kicker Resonator in MEIC Electron Circular Cooler Ring	cavity, kicker, simulation, impedance	63
	Y.L. Huang IMP/CAS, Lanzhou, People's Republic of China R.A. Rimmer, H. Wang, S. Wang JLab, Newport News, Virginia, USA
	An ultra-fast harmonic kicker consisted of normal conducting resonators with high transverse shunt impedance thus less RF power consumption was designed for the proposed Medium energy Electron Ion Collider (MEIC). In the prototype design, four quarter wave resonator (QWR) based deflecting cavities are used to generate ten cosine harmonic waveforms, the electron bunches passing through these cavities will experience an integral effect of all the harmonic fields, thus every 10th bunch in a continues bunch train of 10th harmonic bunch frequency will be kicked while all the other bunches un-kicked. Ten harmonic waves are distributed in the four cavities with the proportion of 5:3:1:1. For the multi-frequency cavities, a great challenge is to tune each harmonic to be exact frequency. In this paper, the taper and tuning scheme for the 5-modes cavity is presented. Five taper points in the inner conductor are chosen to make the five frequencies to be odd harmonics. Five stub tuners on the outer conductor are used to tune every harmonic back to its target frequency from the manufacturing errors. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUWAUD01	Status, Recent Results and Prospect of the International Muon Ionization Cooling Experiment (MICE)	detector, alignment, solenoid, emittance	67
	C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Muon accelerators have been proposed as a means to produce intense, high energy muon beams for particle physics. Designs call for beam cooling to provide suitable beams. Existing cooling schemes cannot operate on time scales that are competitive with the muon lifetime. Ionisation cooling has been proposed as a means to achieve sufficient cooling, but it has never been demonstrated practically. In the Muon Ionisation Cooling Experiment (MICE), based at the Rutherford Appleton Laboratory, ionisation cooling will be demonstrated. MICE Step IV is currently in progress and will be completed in 2016. Muons are brought onto an absorber, resulting in a reduction of momentum and hence reduction of normalised transverse emittance. The full Demonstration of Ionisation Cooling will take place in 2017. An extra magnet module and RF cavities will be installed, as in a cell of a cooling channel. This will enable demonstration of reduction of emittance and subsequent re-acceleration, both critical components for a realistic ionisation cooling channel.
	Slides TUWAUD01 [3.280 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXAUD02	Project of Electron Cooler for NICA	collider, ion, solenoid, luminosity	82
	I.N. Meshkov, E.V. Ahmanova, A.G. Kobets, O. Orlov, V.I. Shokin, A.A. Sidorin, S. Yakovenko JINR, Dubna, Moscow Region, Russia M.N. Kokurkin, N.Yu. Lysov Allrussian Electrotechnical Institute, Moskow, Russia
	The problems of development of high energy electron coolers are discussed on the basis of the existing experience. Necessities of electron cooling application to NICA collider are considered and the project parameters of the electron cooler at NICA collider are presented. Electron cooler of the NICA Collider is under design and development of its elements at JINR. It will provide the formation of an intense ion beam and maintain it in the electron energy range of 0.5'2.5 MeV. To achieve the required energy of the electrons all the elements of the Cooler are placed in the tanks filled with sulfur hexafluoride (SF6) gas under pressure of 6 atm. For testing the Cooler elements the test bench «Recuperator» is used and upgraded. The results of testing of the prototypes of the Cooler elements and the present stage of the technical design of the Cooler are described in this paper.
	Slides TUXAUD02 [5.849 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUYAUD03	Formation of Bunched Electron Beam at the Electron Cooler of CSRm	ion, controls, gun, cathode	85
	X.D. Yang, J. Li, X.M. Ma, L.J. Mao, M.T. Tang, T.L. Yan IMP/CAS, Lanzhou, People's Republic of China
	The motivation for formation of bunched electron beam at the electron cooler of CSRm is based on the three requirements. Firstly, the high energy electron cooling, especially, the ion beam with TeV energy, the bunched electron beam for cooling would be easier than the DC operating mode. Secondly, the electric field induced by the intensity modulated electron beam will be used for the suppression of instability developed in the high intensity ion beam after accumulation with the help of electron cooling, Thirdly, the electron beam was required to turn on and off in the different period of the atomic physics experiments. Some initial design and consideration were presented in this paper. And also the current situation and condition of CSRm electron cooler were described here. An off-line testbench will be established in the laboratory, and the test and the optimization will be explored in this experimentation. The validity of this system will be verified in the near future. The procedure of the modulation on the voltage of control electrode in the electron gun of the CSRm cooler was discussed. The scheme of off-line measurement was devised according to the progress.
	Slides TUYAUD03 [4.038 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUYAUD04	Development of an Ultra Fast RF Kicker for an ERL-based Electron Cooler	kicker, emittance, flattop, simulation	89
	A.V. Sy, A.J. Kimber, J. Musson JLab, Newport News, Virginia, USA
	The staged approach to electron cooling proposed for Jefferson Lab's Medium Energy Electron-Ion Collider (MEIC) utilizes bunched beam electron cooling with a single-pass energy recovery linac (ERL) for cooling in the ion collider ring. Possible luminosity upgrades make use of an ERL and full circulator ring and will require ultra-fast kickers that are beyond current technology. A novel approach to generating the necessary ultra fast (ns-level) RF kicking pulse involves the summation of specific subharmonics of the cooling electron bunch frequency; the resultant kicking pulse is then naturally constrained to have rise and fall times equal to the electron bunch frequency. The uniformity of such a pulse and its effects on the beam dynamics of the cooling electron bunch are discussed.
	Slides TUYAUD04 [2.086 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF02	Development of the Electron Cooling Simulation Program for MEIC	ion, emittance, collider, simulation	101
	H. Zhang, J. Chen, R. Li JLab, Newport News, Virginia, USA H. Huang, L. Luo ODU, Norfolk, Virginia, USA
	Funding: Work supported by the Department of Energy, Laboratory Directed Research and Development Funding, under Contract No. DE-AC05-06OR23177 In the medium energy electron ion collider (MEIC) project at Jefferson Lab, the traditional electron cooling technique is used to reduce the ion beam emittance at the booster ring, and to compensate the intrabeam scattering effect and maintain the ion beam emittance during collision at the collider ring. A DC cooler at the booster ring and a bunched beam cooler at the collider ring are proposed. To fulfil the requirements of the cooler design for MEIC, we are developing a new program, which allows us to simulate the following cooling scenarios: DC cooling to coasting ion beam, DC cooling to bunched ion beam, bunched cooling to bunched ion beam, and bunched cooling to coasting ion beam. The new program has been benchmarked with existing code in aspect of accuracy and efficiency. The new program will be adaptive to the modern multicore hardware. We will present our models and some simulation results.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF08	High Efficiency Electron Collector for the High Voltage Electron Cooling System of COSY	high-voltage, vacuum, gun, experiment	112
	M.I. Bryzgunov, A.V. Bubley, V.A. Chekavinskiy, I.A. Gusev, A.V. Ivanov, M.N. Kondaurov, V.M. Panasyuk, V.V. Parkhomchuk, D.N. Pureskin, A.A. Putmakov, V.B. Reva, D.V. Senkov, D.N. Skorobogatov BINP SB RAS, Novosibirsk, Russia V.B. Reva NSU, Novosibirsk, Russia
	A high efficiency electron collector for the COSY high voltage electron cooling system was developed. The main feature of the collector is usage of special insertion (Wien filter) before the main collector, which deflects secondary electron flux to special secondary collector, preventing them fly to the electrostatic tube. In first tests of the collector in COSY cooler efficiency of recuperation better then 10^-5 was reached. Before assembling of the cooler in Jülich upgrades of the collector and electron gun were made. After the upgrade efficiency better then 10-6 was reached. Design and testing results of the collector are described.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF09	Decoupling and Matching of Electron Cooling Section in the MEIC Ion Collider Ring	ion, solenoid, collider, coupling	116
	G.H. Wei, F. Lin, V.S. Morozov, H. Zhang JLab, Newport News, Virginia, USA
	To get a luminosity level of 10³³ cm^-2 s^-1 at all design points of the MEIC, small transverse emittance is necessary in the ion collider ring, which is achieved by an electron cooling. And for the electron cooling, two solenoids are used to create a cooling environment of temperature exchange between electron beam and ion beam. However, the solenoids can also cause coupling and matching problem for the optics of the MEIC ion ring lattice. Both of them will have influences on the IP section and other areas, especially for the beam size, Twiss parameters, and nonlinear effects. A symmetric and flexible method is used to deal with these problems. With this method, the electron cooling section is merged into the ion ring lattice elegantly.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF10	Harmonic Stripline Kicker for MEIC Bunched Beam Cooler	kicker, impedance, ion, feedback	120
	J. Guo, H. Wang JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 In the current MEIC design, the ion collider ring needs to be cooled by a bunched electron beam of up to 200 mA 55 MeV, with the possibility to upgrade to 1.5 A. Although it's not impossible to design and build an ERL to provide such a beam, the technical risk and cost associated with such an ERL will be very high. An alternative is to recirculate the electron bunches in a ring for up to 25 turns until the bunch's quality is degraded, reducing the beam current in the ERL by a factor of 25. This scheme requires a pair of fast kickers that kick one in every 25 bunches. In this paper, we will analyze the electrodynamics of a harmonic stripline kicker for this application, and compare it to a harmonic resonator kicker.
	Poster TUPF10 [1.081 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAUD02	Emittance Growth From Modulated Focusing and Bunched Beam Electron Cooling	emittance, ion, resonance, synchrotron	132
	M. Blaskiewicz, J. Kewisch, C. Montag BNL, Upton, Long Island, New York, USA
	The Low Energy electron Cooling (LEReC) project at Brookhaven employs an energy recovery linac to supply electrons in the 1.6 to 5 MeV range. Along with cooling the stored ion beam these bunches create a coherent space charge field which can cause emittance growth. This process is investigated both analytically and via simulation.
	Slides WEXAUD02 [1.267 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAUD04	Electron Cooling at GSI and FAIR – Status and Latest Activities	ion, experiment, proton, power-supply	136
	J. Roßbach, C. Dimopoulou, M. Steck GSI, Darmstadt, Germany
	The status, function and operation parameters of the existing and future electron coolers at GSI and FAIR are presented. We report on the progress of the ongoing recommissioning of the former CRYRING storage ring with its electron cooler at GSI. First systematic results on the cooling of a 400 MeV proton beam during the last ESR beamtime are discussed. Motivated by the demands of the experiments on high stability, precise monitoring and even absolute determination of the velocity of the electrons i.e. the velocity of the electron- cooled ion beams, high precision measurements on the electron cooler voltage at the ESR were carried out towards the refurbishment of the main high-voltage supply of the cooler. Similar concepts are underway for the CRYRING cooler high-voltage system.
	Slides WEXAUD04 [23.579 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THWCR04	RF Technologies for Ionization Cooling Channels	cavity, vacuum, plasma, ion	145
	B.T. Freemire, Y. Torun IIT, Chicago, Illinois, USA D.L. Bowring, A. Moretti, A.V. Tollestrup, K. Yonehara Fermilab, Batavia, Illinois, USA A.V. Kochemirovskiy University of Chicago, Chicago, Illinois, USA D. Stratakis BNL, Upton, Long Island, New York, USA
	Funding: Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359 Ionization cooling is the preferred method of cooling a muon beam for the purposes of a bright muon source. This process works by sending a muon beam through an absorbing material and replacing the lost longitudinal momentum with radio frequency (RF) cavities. To maximize the effect of cooling, a small optical beta function is required at the locations of the absorbers. Strong focusing is therefore required, and as a result normal conducting RF cavities must operate in external magnetic fields on the order of 10 Tesla. Vacuum and high pressure gas filled RF test cells have been studied at the MuCool Test Area at Fermilab. Methods for mitigating breakdown in both test cells, as well as the effect of plasma loading in the gas filled test cell have been investigated. The results of these tests, as well as the current status of the two leading muon cooling channel designs, will be presented.
	Slides THWCR04 [46.592 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRXAUD02	Lepta - the Facility for Fundamental and Applied Research	positron, vacuum, cryogenics, resonance	179
	A.G. Kobets, E.V. Ahmanova, P. Horodek, I.N. Meshkov, O. Orlov, A.A. Sidorin JINR, Dubna, Moscow Region, Russia M.K. Eseev NAFU, Arkhangelsk, Russia
	The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron cooling system. The project positron energy is of 2 ' 10 keV. The main goal of the facility is to generate an intense flux of positronium atoms ' the bound state of electron and positron. Storage ring of LEPTA facility was commissioned in September 2004 and is under development up to now. The positron injector has been constructed in 2005 / 2010, and beam transfer channel ' in 2011. By the end of August 2011 the experiments on injection into the ring of electrons and positrons stored in the trap were carried out. In 2012 - 2015, the LEPTA trap optimization and new experiments on accumulation of electrons and positrons in the trap has been performed. Furthermore new cooler for positrons source has been designed and manufactured, its assembling is in progress. The recent results are presented here.
	Slides FRXAUD02 [4.124 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOXAUD02

Experimental Observation of Longitudinal Electron Cooling of DC and Bunched Proton Beam at 2425 MeV/c at COSY

proton, simulation, experiment, vacuum

10

V.B. Reva, M.I. Bryzgunov, V.V. Parkhomchuk
BINP SB RAS, Novosibirsk, Russia
V. Kamerdzhiev, T. Katayama, R. Stassen, H. Stockhorst
FZJ, Jülich, Germany

The 2 MeV electron cooling system for COSY-Julich started operation in 2013 years. The cooling process was observed in the wide energy range of the electron beam from 100 keV to 908 keV. Vertical, horizontal and longitudinal cooling was tested at bunched and continuous beams. The cooler was operated with electron current up to 0.9 A. This report deals with the description of the experimental observation of longitudinal electron cooling of DC and bunched proton beam at 2425 MeV/c at COSY.

Slides MOXAUD02 [10.860 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF02

The Green Energy Turbine as Turbo Generator for Powering the HV-Solenoids at a Relativistic Electron Cooler

solenoid, high-voltage, experiment, emittance

29

A. Hofmann, K. Aulenbacher, M.W. Bruker, J. Dietrich, T. Weilbach
HIM, Mainz, Germany
V.V. Parkhomchuk, V.B. Reva
BINP SB RAS, Novosibirsk, Russia

One challenge in the development of a relativistic electron cooler is the powering of components, e.g. HV-solenoids, which sit on different potentials within a high voltage vessel and need a floating power supply. Within a design study, BINP SB RAS Novosibirsk has proposed two possibilities to build a power supply in a modular way. The first proposal is to use two cascade transformers per module. One cascade transformer powers 22 small HV-solenoids; the second one should generate the acceleration/deceleration voltage. The cascade transformers are fed by a turbo generator, which is powered by a gas under high pressure which is generated outside of the vessel. The second possibility is to use two big HV-solenoids per module. In this proposal, the HV-solenoids are powered directly by a turbo generator. For both concepts, a suitable turbo generator is essential. A potential candidate for the turbo generator could be the Green Energy Turbine (GET) from the company DEPRAG, which works with dry air and delivers a power of 5 kW. At the Helmholtz-Institut Mainz two GETS are tested. After an introduction, we present our experience with the GET and give an overview of the further road map.

Poster MOPF02 [3.424 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF03

Electron Lenses and Cooling for the Fermilab Integrable Optics Test Accelerator

optics, proton, space-charge, lattice

32

G. Stancari, A.V. Burov, V.A. Lebedev, S. Nagaitsev, E. Prebys, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the US Department of Energy.
Recently, the study of integrable Hamiltonian systems has led to nonlinear accelerator lattices with one or two transverse invariants and wide stable tune spreads. These lattices may drastically improve the performance of high-intensity machines, providing Landau damping to protect the beam from instabilities, while preserving dynamic aperture. The Integrable Optics Test Accelerator (IOTA) is being built at Fermilab to study these concepts with 150-MeV pencil electron beams (single-particle dynamics) and 2.5-MeV protons (dynamics with self fields). One way to obtain a nonlinear integrable lattice is by using the fields generated by a magnetically confined electron beam (electron lens) overlapping with the circulating beam. The required parameters are similar to the ones of existing devices. In addition, the electron lens will be used in cooling mode to control the brightness of the proton beam and to measure transverse profiles through recombination. More generally, it is of great interest to investigate whether nonlinear integrable optics allows electron coolers to exceed limitations set by both coherent or incoherent instabilities excited by space charge.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF05

A Cooling Storage Ring for an Electron-Ion Collider

ion, simulation, collider, booster

36

J. Gerity, P.M. McIntyre
Texas A&M University, College Station, USA

Electron cooling offers performance advantages to the design of an electron-ion collider. A first design of a 6 GeV/u storage ring for the cooling of ions in MEIC is presented, along with some remarks on the particulars of electron cooling in this ring.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF06

Quantification of the Electron Plasma in TItan's Cooler Penning Trap

ion, detector, plasma, TRIUMF

39

B.A. Kootte, B. Barquest, U. Chowdhury, J. Even, M. Good, A.A. Kwiatkowski, D. Lascar, K.G. Leach, A. Lennarz, D.A. Short
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
M. Alanssari
Universität Muenster, Physikalisches Institut, Muenster, Germany
C. Andreoiu
SFU, Burnaby, BC, Canada
J. Bale, J. Dilling, A. Finlay, A.A. Gallant, E. Leistenschneider
UBC & TRIUMF, Vancouver, British Columbia, Canada
D. Frekers
Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, Münster, Germany
G. Gwinner
University of Manitoba, Manitoba, Canada
R. Klawitter
Heidelberg University, Physics Institute, Heidelberg, Germany
T.T. Li
UW/Physics, Waterloo, Ontario, Canada
A.J. Mayer
University of Calgary, NW Calgary, Alberta, Canada
R. Schupp
MPI, Muenchen, Germany

Funding: Funded by Natural Sciences and Engineering Research Council of Canada (NSERC)
Modern rare isotope facilities provide beams of shortlived radionuclides primarily for studies in the field of nuclear structure, nuclear astrophysics, and low energy particle physics. At these facilities, many activities such as re-acceleration, improvement of resolving power, and precision experimental measurements require charge breeding of ions. However, the charge breeding process can increase the energy spread of an ion bunch, adversely affecting the experiment. A Cooler Penning Trap (CPET) is being developed to address such an energy spread by means of sympathetic electron cooling of the Highly Charged Ion bunches to . 1 eV/q. Recent work has focused on developing a strategy to effectively detect the trapped electron plasma without obstructing the passage of ions through the beamline. The first offline tests demonstrate the ability to trap and detect more than 10⁸ electrons. This was achieved by using a novel wire mesh detector as a diagnostic tool for the electrons.
* E.M. Burbidge et al, Rev Mod Phys, 29 547 (1957)
** V.V. Simon et al, Phys Rev C, 85 064308 (2012)
*** Z. Ke et al, Hyp Int, 173 103 (2006)
**** U. Chowdhury et al, AIP Conf Proc, 1640 120 (2015)

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF08

Secondary Electron Measurements at the HIM Electron Cooler Test Set-Up

simulation, operation, dipole, optics

48

M.W. Bruker, K. Aulenbacher, J. Dietrich, A. Hofmann, T. Weilbach
HIM, Mainz, Germany

The planned advances in electron cooling technology aimed at improving the operation of future hadron storage rings include an increase in electron beam current and acceleration voltage. A test set-up has been built at Helmholtz-Insitut Mainz (HIM) to optimize the recuperation efficiency of such high-current beams in energy recovery operation, requiring a thorough understanding of their interaction with external electric and magnetic fields, such as those found in a Wien velocity filter. Beam diagnostics are carried out using a BPM and current-sensing scraper electrodes. At present, the set-up can be successfully operated at U=17 kV, I=600 mA, showing a relative secondary electron current of about 2·10^-4. We present the current state of the project and its objectives for the foreseeable future.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF10

Design Beam Diagnostic System for Optical Stochastic Cooling at IOTA Ring

undulator, radiation, synchrotron, kicker

55

K. Yonehara, V.A. Lebedev
Fermilab, Batavia, Illinois, USA
J.A. Maloney
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Validation test of optical stochastic cooling (OSC) with 100 MeV electron beam is designed at IOTA ring at Fermilab. A beam diagnostic system for the test is discussed in this paper. The beam position and bunch length will be measured by using a standard button-pickup BPM; while the beam emittance will be measured by using a CCD-based synchrotron light detector. Especially, accurate time measurement is essential to carry out OSC experiments with a single particle. Desired time resolution is the order of 100 ps to study the cooling decrement in various lattice parameters. SiPM is an attractive solid-state device to detect a time domain synchrotron radiation photon. It can realize a fast rise time < 100 ps with a short time width 1-2 ns FWHM and its quantum efficiency is > 40 % at 420 nm. The beam instrumentation required to tune timing in the OSC insert is also discussed. It is based on the interference of radiation coming from the pickup and kicker undulators.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF12

N-body Code to Demonstrate Electron Cooling

proton, ion, booster, emittance

59

S. Abeyratne, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA
B. Erdelyi
ANL, Argonne, USA

In the Electron Ion Collider (EIC), the collision between the electron beam and the proton, or heavy ion, beam results in emittance growth of the proton beam. Electron cooling, where an electron beam and the proton beam co-propagate, is the desired cooling method to cool or mitigate the emittance growth of the proton beam. The pre-booster, the larger booster, and the collider ring in EIC are the major components that require electron cooling. To study the cooling effect, we previously proposed Particles' High order Adaptive Dynamics (PHAD) code that uses the Fast Multiple Method (FMM) to calculate the Coulomb interactions among charged particles. We further used the Strang splitting technique to improve the code's efficiency and used Picard iteration-based novel integrators to maintain very high accuracy. In this paper we explain how this code is used to treat relativistic particle collisions. We are able calculate the transverse emittances of protons and electrons in the cooling section while still maintaining high accuracy. This presentation will be an update on progress with the parallelization of the code and the current status of production runs.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPF13

Taper and Tuner Scheme of a Multi-Frequency Cavity for the Fast Kicker Resonator in MEIC Electron Circular Cooler Ring

cavity, kicker, simulation, impedance

63

Y.L. Huang
IMP/CAS, Lanzhou, People's Republic of China
R.A. Rimmer, H. Wang, S. Wang
JLab, Newport News, Virginia, USA

An ultra-fast harmonic kicker consisted of normal conducting resonators with high transverse shunt impedance thus less RF power consumption was designed for the proposed Medium energy Electron Ion Collider (MEIC). In the prototype design, four quarter wave resonator (QWR) based deflecting cavities are used to generate ten cosine harmonic waveforms, the electron bunches passing through these cavities will experience an integral effect of all the harmonic fields, thus every 10th bunch in a continues bunch train of 10th harmonic bunch frequency will be kicked while all the other bunches un-kicked. Ten harmonic waves are distributed in the four cavities with the proportion of 5:3:1:1. For the multi-frequency cavities, a great challenge is to tune each harmonic to be exact frequency. In this paper, the taper and tuning scheme for the 5-modes cavity is presented. Five taper points in the inner conductor are chosen to make the five frequencies to be odd harmonics. Five stub tuners on the outer conductor are used to tune every harmonic back to its target frequency from the manufacturing errors.
Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUWAUD01

Status, Recent Results and Prospect of the International Muon Ionization Cooling Experiment (MICE)

detector, alignment, solenoid, emittance

67

C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Muon accelerators have been proposed as a means to produce intense, high energy muon beams for particle physics. Designs call for beam cooling to provide suitable beams. Existing cooling schemes cannot operate on time scales that are competitive with the muon lifetime. Ionisation cooling has been proposed as a means to achieve sufficient cooling, but it has never been demonstrated practically. In the Muon Ionisation Cooling Experiment (MICE), based at the Rutherford Appleton Laboratory, ionisation cooling will be demonstrated. MICE Step IV is currently in progress and will be completed in 2016. Muons are brought onto an absorber, resulting in a reduction of momentum and hence reduction of normalised transverse emittance. The full Demonstration of Ionisation Cooling will take place in 2017. An extra magnet module and RF cavities will be installed, as in a cell of a cooling channel. This will enable demonstration of reduction of emittance and subsequent re-acceleration, both critical components for a realistic ionisation cooling channel.

Slides TUWAUD01 [3.280 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXAUD02

Project of Electron Cooler for NICA

collider, ion, solenoid, luminosity

82

I.N. Meshkov, E.V. Ahmanova, A.G. Kobets, O. Orlov, V.I. Shokin, A.A. Sidorin, S. Yakovenko
JINR, Dubna, Moscow Region, Russia
M.N. Kokurkin, N.Yu. Lysov
Allrussian Electrotechnical Institute, Moskow, Russia

The problems of development of high energy electron coolers are discussed on the basis of the existing experience. Necessities of electron cooling application to NICA collider are considered and the project parameters of the electron cooler at NICA collider are presented. Electron cooler of the NICA Collider is under design and development of its elements at JINR. It will provide the formation of an intense ion beam and maintain it in the electron energy range of 0.5'2.5 MeV. To achieve the required energy of the electrons all the elements of the Cooler are placed in the tanks filled with sulfur hexafluoride (SF6) gas under pressure of 6 atm. For testing the Cooler elements the test bench «Recuperator» is used and upgraded. The results of testing of the prototypes of the Cooler elements and the present stage of the technical design of the Cooler are described in this paper.

Slides TUXAUD02 [5.849 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUYAUD03

Formation of Bunched Electron Beam at the Electron Cooler of CSRm

ion, controls, gun, cathode

85

X.D. Yang, J. Li, X.M. Ma, L.J. Mao, M.T. Tang, T.L. Yan
IMP/CAS, Lanzhou, People's Republic of China

The motivation for formation of bunched electron beam at the electron cooler of CSRm is based on the three requirements. Firstly, the high energy electron cooling, especially, the ion beam with TeV energy, the bunched electron beam for cooling would be easier than the DC operating mode. Secondly, the electric field induced by the intensity modulated electron beam will be used for the suppression of instability developed in the high intensity ion beam after accumulation with the help of electron cooling, Thirdly, the electron beam was required to turn on and off in the different period of the atomic physics experiments. Some initial design and consideration were presented in this paper. And also the current situation and condition of CSRm electron cooler were described here. An off-line testbench will be established in the laboratory, and the test and the optimization will be explored in this experimentation. The validity of this system will be verified in the near future. The procedure of the modulation on the voltage of control electrode in the electron gun of the CSRm cooler was discussed. The scheme of off-line measurement was devised according to the progress.

Slides TUYAUD03 [4.038 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUYAUD04

Development of an Ultra Fast RF Kicker for an ERL-based Electron Cooler

kicker, emittance, flattop, simulation

89

A.V. Sy, A.J. Kimber, J. Musson
JLab, Newport News, Virginia, USA

The staged approach to electron cooling proposed for Jefferson Lab's Medium Energy Electron-Ion Collider (MEIC) utilizes bunched beam electron cooling with a single-pass energy recovery linac (ERL) for cooling in the ion collider ring. Possible luminosity upgrades make use of an ERL and full circulator ring and will require ultra-fast kickers that are beyond current technology. A novel approach to generating the necessary ultra fast (ns-level) RF kicking pulse involves the summation of specific subharmonics of the cooling electron bunch frequency; the resultant kicking pulse is then naturally constrained to have rise and fall times equal to the electron bunch frequency. The uniformity of such a pulse and its effects on the beam dynamics of the cooling electron bunch are discussed.

Slides TUYAUD04 [2.086 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF02

Development of the Electron Cooling Simulation Program for MEIC

ion, emittance, collider, simulation

101

H. Zhang, J. Chen, R. Li
JLab, Newport News, Virginia, USA
H. Huang, L. Luo
ODU, Norfolk, Virginia, USA

Funding: Work supported by the Department of Energy, Laboratory Directed Research and Development Funding, under Contract No. DE-AC05-06OR23177
In the medium energy electron ion collider (MEIC) project at Jefferson Lab, the traditional electron cooling technique is used to reduce the ion beam emittance at the booster ring, and to compensate the intrabeam scattering effect and maintain the ion beam emittance during collision at the collider ring. A DC cooler at the booster ring and a bunched beam cooler at the collider ring are proposed. To fulfil the requirements of the cooler design for MEIC, we are developing a new program, which allows us to simulate the following cooling scenarios: DC cooling to coasting ion beam, DC cooling to bunched ion beam, bunched cooling to bunched ion beam, and bunched cooling to coasting ion beam. The new program has been benchmarked with existing code in aspect of accuracy and efficiency. The new program will be adaptive to the modern multicore hardware. We will present our models and some simulation results.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF08

High Efficiency Electron Collector for the High Voltage Electron Cooling System of COSY

high-voltage, vacuum, gun, experiment

112

M.I. Bryzgunov, A.V. Bubley, V.A. Chekavinskiy, I.A. Gusev, A.V. Ivanov, M.N. Kondaurov, V.M. Panasyuk, V.V. Parkhomchuk, D.N. Pureskin, A.A. Putmakov, V.B. Reva, D.V. Senkov, D.N. Skorobogatov
BINP SB RAS, Novosibirsk, Russia
V.B. Reva
NSU, Novosibirsk, Russia

A high efficiency electron collector for the COSY high voltage electron cooling system was developed. The main feature of the collector is usage of special insertion (Wien filter) before the main collector, which deflects secondary electron flux to special secondary collector, preventing them fly to the electrostatic tube. In first tests of the collector in COSY cooler efficiency of recuperation better then 10^-5 was reached. Before assembling of the cooler in Jülich upgrades of the collector and electron gun were made. After the upgrade efficiency better then 10-6 was reached. Design and testing results of the collector are described.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF09

Decoupling and Matching of Electron Cooling Section in the MEIC Ion Collider Ring

ion, solenoid, collider, coupling

116

G.H. Wei, F. Lin, V.S. Morozov, H. Zhang
JLab, Newport News, Virginia, USA

To get a luminosity level of 10³³ cm^-2 s^-1 at all design points of the MEIC, small transverse emittance is necessary in the ion collider ring, which is achieved by an electron cooling. And for the electron cooling, two solenoids are used to create a cooling environment of temperature exchange between electron beam and ion beam. However, the solenoids can also cause coupling and matching problem for the optics of the MEIC ion ring lattice. Both of them will have influences on the IP section and other areas, especially for the beam size, Twiss parameters, and nonlinear effects. A symmetric and flexible method is used to deal with these problems. With this method, the electron cooling section is merged into the ion ring lattice elegantly.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPF10

Harmonic Stripline Kicker for MEIC Bunched Beam Cooler

kicker, impedance, ion, feedback

120

J. Guo, H. Wang
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
In the current MEIC design, the ion collider ring needs to be cooled by a bunched electron beam of up to 200 mA 55 MeV, with the possibility to upgrade to 1.5 A. Although it's not impossible to design and build an ERL to provide such a beam, the technical risk and cost associated with such an ERL will be very high. An alternative is to recirculate the electron bunches in a ring for up to 25 turns until the bunch's quality is degraded, reducing the beam current in the ERL by a factor of 25. This scheme requires a pair of fast kickers that kick one in every 25 bunches. In this paper, we will analyze the electrodynamics of a harmonic stripline kicker for this application, and compare it to a harmonic resonator kicker.

Poster TUPF10 [1.081 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAUD02

Emittance Growth From Modulated Focusing and Bunched Beam Electron Cooling

emittance, ion, resonance, synchrotron

132

M. Blaskiewicz, J. Kewisch, C. Montag
BNL, Upton, Long Island, New York, USA

The Low Energy electron Cooling (LEReC) project at Brookhaven employs an energy recovery linac to supply electrons in the 1.6 to 5 MeV range. Along with cooling the stored ion beam these bunches create a coherent space charge field which can cause emittance growth. This process is investigated both analytically and via simulation.

Slides WEXAUD02 [1.267 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAUD04

Electron Cooling at GSI and FAIR – Status and Latest Activities

ion, experiment, proton, power-supply

136

J. Roßbach, C. Dimopoulou, M. Steck
GSI, Darmstadt, Germany

The status, function and operation parameters of the existing and future electron coolers at GSI and FAIR are presented. We report on the progress of the ongoing recommissioning of the former CRYRING storage ring with its electron cooler at GSI. First systematic results on the cooling of a 400 MeV proton beam during the last ESR beamtime are discussed. Motivated by the demands of the experiments on high stability, precise monitoring and even absolute determination of the velocity of the electrons i.e. the velocity of the electron- cooled ion beams, high precision measurements on the electron cooler voltage at the ESR were carried out towards the refurbishment of the main high-voltage supply of the cooler. Similar concepts are underway for the CRYRING cooler high-voltage system.

Slides WEXAUD04 [23.579 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THWCR04

RF Technologies for Ionization Cooling Channels

cavity, vacuum, plasma, ion

145

B.T. Freemire, Y. Torun
IIT, Chicago, Illinois, USA
D.L. Bowring, A. Moretti, A.V. Tollestrup, K. Yonehara
Fermilab, Batavia, Illinois, USA
A.V. Kochemirovskiy
University of Chicago, Chicago, Illinois, USA
D. Stratakis
BNL, Upton, Long Island, New York, USA

Funding: Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359
Ionization cooling is the preferred method of cooling a muon beam for the purposes of a bright muon source. This process works by sending a muon beam through an absorbing material and replacing the lost longitudinal momentum with radio frequency (RF) cavities. To maximize the effect of cooling, a small optical beta function is required at the locations of the absorbers. Strong focusing is therefore required, and as a result normal conducting RF cavities must operate in external magnetic fields on the order of 10 Tesla. Vacuum and high pressure gas filled RF test cells have been studied at the MuCool Test Area at Fermilab. Methods for mitigating breakdown in both test cells, as well as the effect of plasma loading in the gas filled test cell have been investigated. The results of these tests, as well as the current status of the two leading muon cooling channel designs, will be presented.

Slides THWCR04 [46.592 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRXAUD02

Lepta - the Facility for Fundamental and Applied Research

positron, vacuum, cryogenics, resonance

179

A.G. Kobets, E.V. Ahmanova, P. Horodek, I.N. Meshkov, O. Orlov, A.A. Sidorin
JINR, Dubna, Moscow Region, Russia
M.K. Eseev
NAFU, Arkhangelsk, Russia

The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron cooling system. The project positron energy is of 2 ' 10 keV. The main goal of the facility is to generate an intense flux of positronium atoms ' the bound state of electron and positron. Storage ring of LEPTA facility was commissioned in September 2004 and is under development up to now. The positron injector has been constructed in 2005 / 2010, and beam transfer channel ' in 2011. By the end of August 2011 the experiments on injection into the ring of electrons and positrons stored in the trap were carried out. In 2012 - 2015, the LEPTA trap optimization and new experiments on accumulation of electrons and positrons in the trap has been performed. Furthermore new cooler for positrons source has been designed and manufactured, its assembling is in progress. The recent results are presented here.

Slides FRXAUD02 [4.124 MB]

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)